KR101213446B1 - Power supplier for on-line electric vehicle and driving method thereof, control circuit for power supplier - Google Patents

Abstract

PURPOSE: A power supplier for an on-line electric vehicle and a driving method thereof, a control circuit for power supplier are provided to reduce the frequency ripple regardless of the length of a feeder and to generate constant current. CONSTITUTION: A voltage conversion part(200) converts AC power into DC voltage. The voltage conversion part changes the level of the DC voltage. An inverter(210) is connected to a switching element. A control unit classifies the frequency band of current signal. The control unit generates a first control signal and a second controlling signal based on the frequency band. [Reference numerals] (220) Control unit; (230) Load

Description

On-line electric vehicle power feeding device and driving method thereof, control circuit for on-line electric vehicle power feeding device {Power Supplier for On-Line Electric Vehicle and Driving Method Thereof, Control Circuit for Power Supplier}

An embodiment of the present invention relates to a power feeding device for an on-line electric vehicle, a driving method thereof, and a control circuit for a power feeding device for an on-line electric vehicle. More specifically, in the system for supplying high frequency electricity to feeder lines, such as on-line electric vehicles, the feeder for on-line electric vehicles and the driving method thereof, which can generate a constant current with high efficiency and feed the feeder, and control the feeder for on-line electric vehicles It is about a circuit.

The contents described in the following sections provide background information related to the embodiments of the present invention, but it does not constitute a prior art.

Countries around the world are actively supporting the development of eco-friendly vehicles due to tightening environmental regulations, depletion of petroleum resources, and oil price hikes. . Under these circumstances, the development of electric vehicles using electric energy has emerged as one of the representative next generation automobile technologies.

1 is a view showing the structure of a feeder for an online electric vehicle according to the prior art, Figure 2 is a view showing the structure of a feeder for an online electric vehicle according to the prior art.

As shown in FIG. 1, a power supply device for an online electric vehicle according to the related art includes a thyristor rectifier circuit 100 and an inverter 110, and further includes a load 120.

Here, the thyristor rectifier circuit 100 converts AC power of three phases into DC and outputs it to the inverter 110, and the inverter 110 operates at a constant frequency to load the DC voltage provided from the rectifier circuit 100. Will output

Thyristor rectifier circuit 100 has the characteristics of low cost, robustness and high efficiency, but the response is slow to make a ripple of 360 kHz which is 6 times the power frequency.

If the feed line has a large inductance, the conventional feeder compensates through a capacitor, as shown in FIG. To control.

Referring to FIG. 2, the complex impedance ignoring the line resistance of the feeder may be represented by Equation 1.

Where f is the operating frequency of the inverter 110.

If Equation 1 is expressed as the magnitude of impedance again, Equation 2 is obtained.

Conventional online electric vehicles are designed to have an impedance of about 1 to 1.2 Hz for f = 20 kHz. If the line inductance is small, i.e. if the line length is short, the feed line impedance is less than 1 kW, no compensation is required. If the impedance is 1 Ω, the magnitude of the impedance for 360 ㎐ is very small as in <Equation 1>.

<Calculation Formula 1>

However, the thyristor rectifier circuit 100 as in FIG. 1 has a 360 Hz ripple and may not have a higher frequency response. Therefore, if the line has a very low impedance for 360 Hz, a relatively large 360 Hz ripple may appear on the output side. That is, a waveform in which a 20 kHz current is modulated to 360 Hz appears.

If the impedance needs to be compensated with very little as 1.2 Ω or more, that is, to compensate for 1.21 kHz to 1 kHz, the impedance for 20 to 30th harmonics of 360 kHz may be very low, resulting in these frequency ripples.

For example, the impedance for the 25th harmonic can be expressed as <Equation 2>.

<Calculation Formula 2>

As described above, in the conventional power feeding device, its performance varies depending on the size of the inductance according to the length of the feeding line, and in some ranges, the degree of performance degradation occurs very severely. In particular, when the impedance of the line is small, the 360 mA current ripple made by the thyristor rectifier circuit 100 is large, which causes a problem in that the performance of the power feeding device is degraded.

An embodiment of the present invention provides an on-line electric vehicle power feeding device and a driving method thereof, and a control circuit of the on-line electric vehicle power feeding device capable of generating a constant current with high efficiency and supplying the power supply line without being affected by the length of the power feeding line. The purpose is.

The electric power feeding device for an online electric vehicle according to an embodiment of the present invention receives an AC power and converts the DC voltage into a DC voltage, and outputs the voltage by converting the level of the DC voltage by operating by an external first control signal. ; A plurality of switching elements are connected to each other in the form of a bridge between the output side and the other end of the voltage conversion unit, and the plurality of switching elements are controlled by PWM (Pulse Width Modulation) by an external second control signal. An inverter for outputting a voltage; And receiving a feedback of the current signal output from the inverter, classifying a frequency band of the current signal, generating the first control signal and the second control signal based on the divided frequency band, and converting the voltage conversion unit and the It characterized in that it comprises a control unit for controlling the inverter.

The control circuit of the on-line electric vehicle power feeding device according to the embodiment of the present invention receives the current signal output from the inverter by the on / off operation of the switching elements having a bridge form to receive the current signal to the first frequency band signal and A signal separator for dividing and outputting the second frequency band signal; And a rectifying circuit generating a first control signal based on the first frequency band signal and a second control signal based on the second frequency band signal, converting an AC power source into a DC voltage and providing the inverter to the inverter. And a controller for providing a first control signal and the second control signal to the inverter.

According to an embodiment of the present invention, a method for driving an electric power feeding device for an online electric vehicle is provided with feedback of a current signal output from an inverter by an on / off operation of a switching device having a bridge shape, and receives the current signal as a first frequency band signal. Dividing and outputting the signal into a second frequency band signal; And a rectifying circuit generating a first control signal based on the first frequency band signal and a second control signal based on the second frequency band signal, converting an AC power source into a DC voltage and providing the inverter to the inverter. And providing a first control signal and providing the second control signal to the inverter.

According to an embodiment of the present invention, regardless of the length of the feeder line, the frequency ripple can be reduced to generate a constant current with high efficiency and supply it to the feeder line to improve the performance of the on-line electric vehicle feeder.

1 is a view showing the structure of a power feeding device for an online electric vehicle according to the prior art,
2 is a view showing a structure of a feeder for an online electric vehicle according to the prior art;
3 is a view showing the structure of a power feeding device for an online electric vehicle according to an embodiment of the present invention;
4 is a diagram illustrating a detailed structure of a controller of FIG. 3;
5 is an exemplary diagram of PWM control waveforms of the inverter shown in FIG. 3.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

3 is a view showing the structure of a power feeding device for an online electric vehicle according to an embodiment of the present invention.

As shown in FIG. 3, a power feeding device for an on-line electric vehicle according to an embodiment of the present invention includes a voltage converter 200, an inverter 210, and a controller 220, and a load such as a primary coil of a transformer. 230 may be further included.

Here, the voltage converter 200 receives, for example, three-phase AC power and converts the DC voltage into an output. The voltage converter 200 according to the embodiment of the present invention preferably includes a thyristor converter as shown in FIG. 3, and the thyristor converter may include a rectifying circuit and a smoothing circuit. The rectifier circuit is preferably a half-wave or full-wave rectifier circuit formed by connecting a thyristor element in the form of a pole or a bridge. Since the output voltage of the rectifier circuit includes a pulsation voltage (Ripple), the smoothing circuit serves to reduce or eliminate ripple.

Although not separately shown in the drawings, the voltage converter 200 according to the embodiment of the present invention may further include a DC / DC converter or the like interworking with the thyristor converter of FIG. 3. Here, the DC / DC converter converts and outputs the level of the DC voltage provided through the thyristor converter, more precisely, the smoothing circuit. For example, a buck type DC / DC converter reduces the output voltage of the smoothing circuit. Play a role.

In addition, the voltage converter 200 is controlled by the controller 220. More specifically, the thyristor elements of the rectifier circuit constituting the voltage converter 200 control the firing angle to the full range under the control of the controller 220. Here, the firing angle refers to the electrical angle of the anode when the thyristor element is turned on, and means the delay time of the gate signal that turns on the thyristor element. For example, the thyristor elements of the rectifier circuit have a delay time from the controller 220 based on the low frequency band signal when the controller 220 detects the low frequency band signal through the current feedback signal fed back from the load 230. By receiving the adjusted gate signal to control the firing angle to the full range to adjust the level of the DC voltage to provide to the inverter 210.

The inverter 210 includes, for example, a plurality of switching elements S ₁ to S ₄ such as an insulated gate bipolar transistor (IGBT) to generate a switching voltage for an output voltage of the voltage converter 200 as a resonant inverter. . The first and third switching elements S ₁ and S ₃ and the second and fourth switching elements S ₂ and S ₄ are correspondingly and electrically connected one-to-one, respectively, between the both ends of the output of the voltage converter 200. A first leg and a second leg are formed.

Looking at the configuration of the inverter 210 in more detail by taking the IGBT as an example, the collector terminal of the first and second switching elements (S ₁ , S ₂ ) that are part of the first and second legs is the amount of the voltage converter 200. The emitter terminals of the third and fourth switching elements S ₃ and S ₄ , which are connected to the voltage (+ Vcc) terminal and are part of the first and second legs, are connected to the negative voltage (-Vcc) of the voltage converter 200. Connect to the terminal. In addition, the emitter terminals of the first and second switching elements S ₁ and S ₂ are connected to the collector terminals of the third and fourth switching elements S ₃ and S ₄ , respectively, and the connection points are connected to the first and second nodes. It is called. The gate terminals of the first to fourth switching elements S ₁ to S ₄ constituting the first and second legs are connected to the controller 220.

According to this configuration, the first and fourth switching elements S ₁ and S ₄ and the second and third switching elements S ₂ and S ₃ of the inverter 210 operate complementarily to each other. In other words, when the first and fourth switching elements S ₁ and S ₄ are turned on, the second and third switching elements S ₂ and S ₃ are turned off, and the second and third turned off When the three switching elements S ₂ and S ₃ are turned on, the first and fourth switching elements S ₁ and S ₄ which are turned on are operated in a manner that is simultaneously turned off. In this case, the first and fourth switching devices S ₁ and S ₄ and the second and third switching devices S ₂ and S ₃ preferably have a duty rate of 50%. However, when the high frequency band signal is detected from the current feedback signal as a result of the determination of the controller 220, the first and fourth switching elements S ₁ and S ₄ and the second and third switching elements S ₂ of the inverter 210 are detected. , S ₃ respectively outputs a current whose duty ratio is adjusted under the control of the controller 220.

The controller 220 divides the current feedback signal fed back from the load 230 into a low frequency and a high frequency band signal. For example, when the low frequency band signal is detected, the controller 220 controls the rectifier circuit of the voltage converter 200, and the high frequency band signal is When detected, the inverter 210 is controlled. For example, the controller 220 controls the firing angle of the thyristor elements of the rectifier circuit to the full range based on the detected low frequency band signal, and based on the detected high frequency band signal, the first to the second to 4 switching elements (S ₁ ~ S ₄ ) controls the PWM (Pulse Width Modulation) finely in the range of 10 ~ 20% of the half period (T / 2), or simultaneously controls the rectifier circuit and the inverter according to the detection result.

4 is a diagram illustrating a detailed structure of the controller of FIG. 3, and FIG. 5 is an exemplary diagram of a PWM control waveform of the inverter illustrated in FIG. 3.

Referring to FIG. 4 along with FIG. 3, the controller 220 may include a controller 400 and a signal separator 410, and may further include a pulse generator, a triangular wave generator, and the like.

Herein, the controller 400 generates a control signal according to whether the signal component provided from the signal separator 410 is a low frequency band signal or a high frequency band signal to the rectifier circuit of the voltage converter 200 and the inverter 210, respectively. to provide. For example, the controller 400 may use the pulse signal generated by the pulse generator as a control signal to control the rectifier circuit, and use the triangle wave signal of the triangle wave generator to generate the control signal for PWM control of the inverter 210. It is available.

The signal separator 410 includes a low pass filter (LPF) 411 and a band pass filter (BPF) 413. The LPF 411 passes a low band signal among the current feedback signals fed back from the load 230, and the BPF 413 passes a signal of a specific band. According to an embodiment of the present invention, the LPF 411 passes a low frequency band signal of less than 360 Hz, and the BPF 413 preferably passes a band signal including a frequency of 360 Hz.

Looking briefly at the driving process, the control unit 220 receives the current feedback signal from the load 230, the low-frequency and high-frequency band signal through the signal divider 410 including the LPF 411 and BPF 413 Separate.

For example, the controller 220 generates a pulse signal based on the low frequency band signal and provides the generated pulse signal to the voltage converter 200, and generates a PWM signal based on the high frequency band signal and provides the generated PWM signal to the inverter 210.

Here, the thyristor element of the rectifier circuit constituting the voltage converter 200 receives the pulse signal of the controller 220 as a gate signal and controls the firing angle to the full range to adjust the level of the DC voltage to the inverter 210. As a result, the instantaneous control so as not to deviate greatly from the control target DC value reduces the difference with the actual DC voltage compared to the control target DC voltage. Therefore, the ripple of the DC voltage provided from the voltage converter 200 to the inverter 210 is reduced by that much.

In addition, the control unit 220 when the complementary operation of the first and fourth switching elements (S ₁ , S ₄ ) and the second and third switching elements (S ₂ , S ₃ ) constituting the inverter 210, FIG. 5 By generating and providing a PWM control signal having a quasi-square wave shape as shown in (a) of FIG. 5 for the current feedback signal as shown in (b) of (b) to (+) to (-) or (-) to (+) Control to have zero level while switching. As such, the voltage waveform is formed closer to the sine wave compared to the square wave, thereby reducing the harmonic content. In this process, the controller 220 must set β within a range not greater than the load power factor angle α to ensure zero voltage switching (ZVS).

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

For example, in the exemplary embodiment of the present invention, the switching elements are not limited to the IGBT but may include at least one of a junction type FET, a bipolar junction transistor (BJT), a MOS FET, a junction gate FET (JFET), and a diode. Therefore, the gate of the FET series element or the base and gate of the BJT and IGBT series element may be collectively used as the driving stage of the switching element. In addition, the drain of the FET series device or the collector of the BJT, IGBT series device may be referred to as the current inlet of the switching element, the source of the FET series device and the emitter of the BJT, IGBT series device may be referred to as the current outlet. .

In addition, the terms "comprise", "comprise" or "having" described in the specification mean that a corresponding component may be included unless otherwise stated, and thus, other components are excluded. It should be construed that it may further include other components. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Terms used generally, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present invention.

An embodiment of the present invention is applicable to an electric power feeding device for an on-line electric vehicle, a method of driving the device, and a control circuit of an electric power feeding device for an online electric vehicle. In other words, by generating a constant current with high efficiency and supplying it to a feeder line, it is possible to improve the performance of, for example, an on-line electric vehicle feeder.

100: thyristor rectifier circuit 110, 210: inverter
120, 230: load 200: voltage converter
220: control unit 400: controller
410: signal separator 411: low pass filter
413: bandpass filter

Claims (9)

A voltage converter configured to receive an AC power, convert the DC voltage into an output DC voltage, and output the converted DC voltage by operating an external first control signal;
A plurality of switching elements are connected to each other in the form of a bridge between the output side and the other end of the voltage conversion unit, and the plurality of switching elements are controlled by PWM (Pulse Width Modulation) by an external second control signal. An inverter for outputting a voltage; And
The voltage converter and the inverter are generated by receiving the feedback of the current signal output from the inverter and classifying a frequency band of the current signal, and generating the first control signal and the second control signal based on the divided frequency band. Control unit to control
Power feeding device for an online electric vehicle, characterized in that it comprises a. The method of claim 1, wherein the voltage converter,
A thyristor rectifier circuit including a plurality of thyristor elements for controlling a firing angle by the first control signal input as a gate signal, the thyristor rectifier circuit receiving the AC power and converting the rectified voltage into a rectified voltage; And
A smoothing circuit smoothed by receiving the rectified voltage of the thyristor rectifier circuit
Power feeding device for an online electric vehicle, characterized in that it comprises a. The method of claim 1,
The plurality of switching elements are driven by the second control signal on-line electric vehicle power supply device characterized in that it has a zero level when converting from negative voltage to positive voltage or positive voltage to negative voltage. A signal divider configured to receive a feedback of a current signal output from an inverter by an on / off operation of switching devices having a bridge shape and to divide the current signal into a first frequency band signal and a second frequency band signal and output the divided signal; And
A first control signal based on the first frequency band signal and a second control signal based on the second frequency band signal, and converting an AC power source into a DC voltage and providing the inverter to the inverter; A controller providing a control signal, wherein the second control signal is provided to the inverter.
Control circuit of a power feeding device for an online electric vehicle comprising a. 5. The method of claim 4,
The rectifier circuit includes a plurality of thyristor elements,
And the controller controls the firing angle of the thyristor element by applying the first control signal as a gate signal of the thyristor element. 5. The method of claim 4,
The controller generates the second control signal so that the switching elements are turned on / off to have a zero level when converting from negative voltage to positive voltage or positive voltage to negative voltage. . The method according to claim 6,
And the controller sets the section having the zero level in the range of 10 to 20% of the half period (T / 2) for zero voltage switching (ZVS). 5. The method of claim 4,
The AC power source is a 60 kHz three-phase AC power source, wherein the first frequency band signal is less than 360 Hz, which is six times the frequency of the AC power source, and the second frequency band signal is greater than or equal to 360 Hz. Control circuit for on-line electric vehicle feeder. Receiving a current signal output from the inverter by an on / off operation of the switching elements having a bridge shape and dividing the current signal into a first frequency band signal and a second frequency band signal to output the divided signal; And
A first control signal based on the first frequency band signal and a second control signal based on the second frequency band signal, and converting an AC power source into a DC voltage and providing the inverter to the inverter; Providing a control signal, wherein the second control signal is provided to the inverter.
Method for driving a power feeding device for an online electric vehicle, characterized in that it comprises a.

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